Bugs, Cicadas, Aphids, and Scale-insects 189 



FIG. 257. The red orange-scale, Aspidiolus 

 aurantii. a, females, natural size, on leaf; b, 

 female, much enlarged, removed from under 

 waxen scale; c, the scale, composed of wax 

 and exuviae, much enlarged; d, just hatched 

 ycung, much enlarged; e, male, much enlarged. 

 (After Jordan and Kellogg.) 



blackish narrow elongate curved scale, resembling a little an oyster-shell 



in miniature; this is the sometimes serious apple-pest, Mytilaspis pomorum. 



But we have no space to list 



even the most important of 



these degenerate but successful 



insect enemies of our fruit- and 



foliage-trees. 



The devising of remedies for 

 scale attack has been given much 

 attention, and a number of effec- 

 tive means have been discovered 

 for fighting the pests. Probably 

 the most effective of all is the 

 fumigation of infested orchard- 

 trees by hydrocyanic gas. A 

 tent capable of enclosing a whole 

 tree is made, and with this in 

 place hydrocyanic gas is gen- 

 erated under it by pouring 

 about 50 oz. of water into 5 oz. 

 of commercial sulphuric acid and 

 dropping in 15 oz. of cyanide of potassium, these amounts of acid, water, and 

 cyanide being sufficient to fumigate a tree 12 ft. high by 10 ft. in foliage diam- 

 eter; that is, to fumigate about 1000 cu. ft. of space. For larger or smaller trees 

 change the amounts of acid, water, and cyanide proportionally. Of washes 

 to be applied in winter, when the leaves are off, the best is one made of lime 

 50 Ibs., sulphur 50 Ibs., salt 50 Ibs., water 150 gals.; slake the lime with 

 water enough to do it thoroughly, and during the process add the sulphur. 

 Boil one hour with water enough to prevent burning and until the mixture 

 becomes of a deep amber color. Dissolve the salt in water enough to do 

 it quickly and add slowly to the boiling mass. When all is thoroughly 

 mixed together and has actually boiled at least an hour add water enough 

 to make up 150 gals., and apply by spraying or washing while hot. It 

 may be safely applied when the foliage is off to any fruit-tree, garden shrub, 

 or small fruit, and is a very effective "scale-killer." Of sprays for the leaves, 

 kerosene emulsion is undoubtedly the safest and best. For use, undiluted 

 crude petroleum should be entirely untreated and of specific gravity of 43 

 or over on the Beaume scale. Smith has used this oil safely on all ordinary 

 fruit-trees, but advises not applying it to peach-trees. At time of apply- 

 ing, the trees should be dry, the oil of a temperature not below 60 Fahrenheit, 

 and the nozzles should throw a perpetual fine spray. Kerosene emulsion is 

 made by boiling J Ib. of hard soap in i gal. of water and then adding 2 gals. 



